Molybdenum containing targets

ABSTRACT

The invention is directed at sputter targets including 50 atomic % or more molybdenum, a second metal element of titanium, and a third metal element of chromium or tantalum, and deposited films prepared by the sputter targets. In a preferred aspect of the invention, the sputter target includes a phase that is rich in molybdenum, a phase that is rich in titanium, and a phase that is rich in the third metal element.

FIELD OF THE INVENTION

The present invention relates generally to sputter targets, methods forpreparing sputter targets, methods of using the sputter targets inpreparing thin molybdenum containing films, such as those used to makeflat display panels (e.g., thin film transistor-liquid crystal displays)and photovoltaic cells, thin films made by the targets, and productsincorporating the same.

BACKGROUND

Sputter deposition is a technique used to produce a metallic layer invarious manufacturing processes used in the semiconductor and thephotoelectric industries. With advances in the semiconductor andphotoelectric industries, there are needs for sputter targets that meetone or more electrical requirements, durability requirements, andprocessability requirements. For example, there is a need for sputtertargets that are easier to process, that are less expensive, and thatcan be used to produce more uniform films. Furthermore, as the size ofdisplays increases, the economic benefits of even modest improvements inperformance becomes amplified. Slight variations in compositions of asputter target could possibly lead to significant property changes.Moreover, different manners in which a target is made may lead to variedproperties resulting from a target made using the same composition.

Sputter targets made from a metal such as molybdenum, methods forpreparing them, and their use in flat panel displays are described inU.S. Pat. No. 7,336,336B2, and in U.S. Patent Application PublicationNo. 2005/0189401A1 by Butzer et al, published on Sep. 1, 2005, each ofwhich is incorporated herein by reference in its entirety.

Sputter targets containing molybdenum and titanium, methods forpreparing them, and their use in flat panel displays are described inU.S. Pat. No. 7,336,824B2 and in U.S. Patent Application PublicationNos. 2008/0314737A1 by Gaydos et al. published on Dec. 25, 2008,2007/0089984A1 by Gaydos et al., published on Apr. 26, 2007, and2007/0251820A1 by Nitta et al. published on Nov. 1, 2007, each of whichis incorporated herein by reference in its entirety.

Sputter targets containing molybdenum and a second metal are describedin U.S. Patent Application Publication No. 2004/0263055A1 by Chao et al.published on Dec. 30, 2004, 2007/0122649A1 by Lee et al. published onMay 31, 2007, and 2005/0230244A1 by Inoue et al. published on Oct. 20,2005, 2008/0073674A1 by Cho et al. published on Mar. 27, 2008, and2005/0191202A1 by Iwasaki et al. published on Sep. 1, 2005, each ofwhich is incorporated herein by reference in its entirety. In themanufacture of many devices, thin film products are often built up layerby layer with one or more material removal steps (e.g., etching). Toaccommodate a wide selection of materials for enhancing design choice,it is attractive to be able to selectively control thin film etch rate(i.e., the rate of removal of material by etching). For example, it isattractive to be able to achieve certain etch rates by selection of anappropriate sputter target. For example, it is attractive to be able toachieve certain etch rates by selection of an appropriate sputtertarget. It may be desirable for a layer deposited from a sputter targetto have an etch rate that is compatible with the etch rate of one ormore other layers (e.g., etch rates that are the same or differ by lessthan about 25%) and/or to have an etch rate that is different (e.g., byabout 25% or more) from the etch rate of one or more other layers.

For example, for some applications there continues to exist a need forsputter targets that produce deposited layers having relatively low etchrates, such as etch rates in ferricyanide solution lower than the etchrate of a layer deposited from a sputter target consisting of 50 atomic% molybdenum and 50 atomic % titanium. There is also a need for sputtertargets for producing deposited layers having one or any combination ofa strong adhesion to substrates, a good barrier properties, an abilityto reduce or prevent the formation of copper silicon compounds (such ascopper silicide) when placed between Si-containing and Cu-containinglayers, or a relatively low electrical resistivity (e.g., about 60 μΩ·cmor less). Additionally, there is a need for sputter targets having oneor more of the above properties, that is prepared from a heterogeneousmaterial that can be processed into a sputter target using a step ofrolling.

SUMMARY OF THE INVENTION

One or more of the above needs may be surprisingly met with a sputtertarget including molybdenum (Mo), titanium (Ti) and a third metalelement, wherein the third metal element is tantalum or chromium. Thepresent invention in its various teachings thus pertain to suchcompositions and sputter targets made with them, as well as resultingthin film products, and associated methods.

One aspect of the invention is a process for preparing a sputter targetand/or a blank that is used to manufacture a sputter target thatincludes a step of blending a first powder containing about 50 atomic %or more molybdenum, a second powder containing about 50 atomic % or moretitanium, and a third powder containing about 50 atomic % or more of athird metal element selected from the group consisting of chromium andtantalum.

Another aspect of the invention is directed at a sputter target and/or ablank that is used to manufacture a sputter target comprising about 40atomic % or more molybdenum, based on the total number of atoms in thesputter target; about 1 atomic % or more titanium, based on the totalnumber of atoms in the sputter target; and about 1 atomic % or more of athird metal element, based on the total number of atoms in the sputtertarget, wherein the third metal element is tantalum or chromium; so thatthe sputter target may be used for preparing a deposited film includingan alloy, the alloy comprising molybdenum, titanium, and the third metalelement.

Another aspect of the invention is directed at a sputter target and/or ablank that is used to manufacture a sputter target including at leastabout 40% by volume, based on the total volume of the sputter target, ofa first phase, wherein the first phase includes at least about 50 atomic% of a first metal element (and thus may be said to be rich in the firstmetal element), wherein the first metal element is molybdenum; fromabout 1 to about 40% by volume, based on the total volume of the sputtertarget, of a second phase, wherein the second phase includes at leastabout 50 atomic % of a second metal element (and thus may be said to berich in the second metal element), wherein the second metal element istitanium, and from about 1 to about 40% by volume, based on the totalvolume of the sputter target, of a third phase, wherein the third phaseincludes at least about 50 atomic % of a third metal element (and thusmay be said to be rich in the second metal element), wherein the thirdmetal element is selected from the group consisting chromium andtantalum, so that the sputter target may be used for preparing adeposited film including an alloy, the alloy comprising molybdenum,titanium and the third metal element. It will be appreciated that in theteachings herein, the third element may be replaced with a combinationof chromium and tantalum.

Another aspect of the invention is directed at a film (e.g., asputter-deposited film) including about 50 atomic % or more molybdenum,about 0.5 atomic % or more titanium, and about 0.5 atomic % or more of athird element selected from the group consisting of chromium andtantalum. By way of example, one such film may have about 50 atomic % toabout 90 atomic % molybdenum, about 5 atomic % to about 30 atomic %titanium, and about 5 atomic % to about 30 atomic % of the third metalelement (e.g., chromium, tantalum, or both). The film may exhibit arelatively low etch rate in accordance with the etch rate teachingsherein.

Another aspect of the invention is directed at a multilayer structureincluding a film deposited from a sputter target described herein.

Another aspect of the invention is directed at a process for depositinga film on a substrate using a sputter target described herein.

The sputter targets of the present invention may advantageously be usedto deposit a film having generally low etch rates. For example, the etchrate of the deposited film in ferricyanide solution at 25° C. may beabout 100 nm/min or less, preferably about 75 nm/min or less, morepreferably about 70 nm/min or less, even more preferably about 68 nm/minor less, even more preferably about 65 nm/min or less, and mostpreferably about 62 nm/min or less. The sputter target may be used todeposit a film having strong adhesion to substrates; having good barrierproperties; that substantially avoids the formation of copper silicidewhen placed between a silicon-containing layer and a copper-containinglayer; having low electrical resistivity; or any combination thereof.Advantageously, the sputter target may be formed of a material capableof being deformed, such as by one or more thermomechanical deformationoperations. For example the sputter target may be prepared from amaterial capable of being rolled (e.g., through one or more rollingoperations), preferably without cracking, so that large sputter targetscan be produced efficiently. It is also possible to make large targetsby joining multiple individually preformed structures (e.g., blocks),e.g., by diffusion bonding via a hot isostatic processing operation,with or without powder between adjoining preformed structures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, titanium, and tantalum using secondaryelectron imaging. The sputter target preferably includes a molybdenumrich phase that includes 50 atomic % or more molybdenum, a titanium richphase that includes 50 atomic % or more titanium, and a tantalum richphase that includes 50 atomic % or more tantalum.

FIG. 2 is an illustrative scanning electron micorgraph of a sputtertarget including molybdenum, titanium and tantalum using backscatteredelectron imaging. The sputter target preferably includes a molybdenumrich phase, a tantalum rich phase, and a titanium rich phase.

FIG. 3A is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, titanium, and tantalum using backscatteredelectron imaging. As illustrated in FIG. 3A, the sputter targetpreferably includes a molybdenum rich phase.

FIG. 3B is an illustrative energy dispersive x-ray spectroscopy graphshowing the frequency distribution of x-rays having energy from 0 to 20keV energy for a region of the sputter target of FIG. 3A. As illustratedin FIG. 3B, the sputter target may include a phase that is essentiallyentirely (e.g., about 90 atomic % or more, preferably about 95 atomic %or more, and more preferably about 98 atomic % or more) molybdenum.

FIG. 4A is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, titanium, and tantalum using backscatteredelectron imaging. As illustrated in FIG. 4A, the sputter targetpreferably includes a titanium rich phase.

FIG. 4B is an illustrative energy dispersive x-ray spectroscopy graphshowing the frequency distribution of x-rays having energy from 0 to 20keV energy for a region of the sputter target of FIG. 4A. FIG. 4Billustrates that the sputter target may have a phase that is essentiallyentirely (e.g., about 90 atomic % or more, preferably about 95 atomic %or more, and more preferably about 98 atomic % or more) titanium.

FIG. 5A is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, titanium, and tantalum using backscatteredelectron imaging. As illustrated in FIG. 5A, the sputter targetpreferably includes a tantalum rich phase.

FIG. 5B is an illustrative energy dispersive x-ray spectroscopy graphshowing the frequency distribution of x-rays having energy from 0 to 20keV energy for a region of the sputter target of FIG. 5A. FIG. 5Billustrates that the sputter target may have a phase that is essentiallyentirely (e.g., about 90 atomic % or more, preferably about 95 atomic %or more, and more preferably about 98 atomic % or more) tantalum.

FIGS. 6A and 6B are illustrative scanning electron micrographs of asurface of sputtered films deposited on a substrate using secondaryelectron imaging. The films are sputtered from a sputter targetincluding a molybdenum rich phase, a titanium rich phase, and a tantalumrich phase. The deposited film preferably include an alloy phasecontaining molybdenum, titanium and tantalum.

FIG. 7 is an illustrative scanning electron micrograph of across-section of a sputtered film deposited on a substrate. The film issputtered from a sputter target including a molybdenum rich phase, atitanium rich phase, and a tantalum rich phase. The deposited filmpreferably includes an alloy phase containing molybdenum, titanium andtantalum. The deposited film may have a columnar morphology, such as themorphology illustrated in FIG. 7.

FIGS. 8A and 8B are illustrative Auger Spectra of a multilayeredstructure including a silicon substrate, a first sputtered layerincluding molybdenum, titanium and tantalum, and a second sputteredlayer of copper. The spectra illustrate the compositions of Cu, Si, Ta,Ti, and Mo versus depth, before (FIG. 8A) and after (FIG. 8B) annealingfor about 30 minutes at about 350° C.

FIGS. 9A and 9B are illustrative Auger Spectra of a multilayeredstructure including an interface between a first sputtered layerincluding molybdenum, titanium and tantalum, and i) a second sputteredlayer of copper (FIG. 9A) and ii) a silicon substrate (FIG. 9B). Thespectra illustrate the compositions of Cu, Si, Ta, Ti, and Mo versusdepth, before and after annealing for about 30 minutes at about 350° C.

FIG. 10 is an illustrative multi-layered structure including a substratelayer, a molybdenum containing layer, and a conductive layer. Themolybdenum containing layer preferably is deposited from a sputtertarget including a molybdenum rich phase, a titanium rich phase and atantalum rich phase.

DETAILED DESCRIPTION

The present invention, in its various aspects, makes use of a uniquecombination of materials to derive an attractive sputter target for usein the manufacture of one or more various devices (e.g., flat paneldisplays) that include a thin film layer, such as a thin film barrierlayer, tie layer, or otherwise. The deposited layers prepared from thesputter targets of the present invention have a surprising combinationof relatively low electrical resistivity, good adhesion to substratesand/or excellent barrier properties. The sputter target preferably istailored to provide deposited layers having low etch rates (e.g., inferricyanide solution).

The sputter targets of the present invention employ three or moredifferent elements to achieve the desired performance properties.Without limitation, suitable sputter targets include material includingor consisting essentially of three metal elements, four metal elements,or five or more metal elements. For example, the sputter target mayinclude or consist substantially of molybdenum (i.e. Mo), titanium(i.e., Ti), and one or more additional metal elements selected from thegroup consisting of vanadium (i.e., V), chromium (i.e., Cr), tantalum(i.e., Ta), and niobium (i.e., Nb). Preferred sputter targets includingor consist substantially of molybdenum, titanium, and a third metalelement selected from tantalum and chromium. Preferred sputter targetsinclude molybdenum, titanium and the third metal element present at atotal concentration of about 60 atomic % or more, more preferably about80 atomic % or more, even more preferably about 95 atomic % or more,even more preferably about 99 atomic % or more, and most preferablyabout 99.5 atomic % or more. Without limitation, deposited layersprepared from the sputter targets of the present invention may includeternary materials and/or quaternary materials.

The sputter targets may be used to produce (e.g., to deposit) a filmhaving at least one molybdenum containing layer (e.g., a barrier layer)that comprises molybdenum (e.g., at a concentration of at least 50atomic % based on the total number of atoms in the molybdenum containinglayer), titanium, and a third metal element. The deposited layer maycontain fewer phases than the sputter target. Without limitation,exemplary deposited layers produced from the sputter target may containone or two phases, whereas the sputter target from which they areprepared, preferably contain at least three phases (e.g., one or morepure metal phases and/or one or more alloy phases). More preferably, thedeposited layer includes or consists essentially of an alloy phase,wherein the alloy includes molybdenum, titanium and the third metalelement. Even more preferably, the deposited layer consists essentiallyof an alloy phase, wherein the alloy includes or consists essentially ofmolybdenum, the titanium and the third metal element. Most preferably,the deposited layer includes or consists essentially of an alloy phase,wherein the alloy includes or consists essentially of molybdenum,titanium and tantalum.

Morphology of the Sputter Target

The sputter target may be a heterogeneous material including a pluralityof phases. The sputter target preferably comprises at least threephases. For example, the target may include one or more first phaseseach comprising at least 50 atomic % molybdenum, one or more secondphases each comprising at least 50 atomic % titanium, and one or morethird phases each comprising at least 50 atomic % of a third metalelement, wherein the third metal element is tantalum or chromium.

A second phase may differ from a first phase in one or any combinationof the following: the concentration of one, two or more elements,density, electrical resistivity, the bravais lattice structure, thesymmetry group, one or more lattice dimensions, or the crystallographicspace group. By way of example, a first phase and a second phase maydiffer in the concentration of one element by about 0.5 wt. % or more,by about 1 wt. % or more, by about 5 wt % or more, or by about 20 wt. %or more. A third phase may differ from a first phase and/or a secondphase in one or any combination of the following: the concentration ofone, two or more elements, density, electrical resistivity, the bravaislattice structure, the symmetry group, one or more lattice dimensions,or the crystallographic space group. By way of example, theconcentration of an element in a third phase my differ from theconcentration of the element in a first phase, in a second phase, orboth, by about 0.5 wt. % or more, by about 1 wt. % or more, by about 5wt. % or more, or by about 20 wt. % or more. The sputter target mayinclude two phases (such as a first phase and a second phase or a thirdphase), wherein the difference between the densities of the two phasesis about 0.1 g/cm³ or more, preferably about 0.3 g/cm³ or more, morepreferably about 0.6 g/cm³, and most preferably about 1.2 g/cm³ or more.

The first phase, the second phase, and the third phase, may eachindependently include crystals characterized by one or more of the 14bravais lattice types. The bravais lattice of a phase may be triclinic,monoclinic (e.g., simple monoclinic or centered monoclinic),orthorhombic (e.g., simple base centered orthorhombic, body centeredorthorhombic, or face-centered orthorhombic), tetragonal (e.g., simpletetragonal or body-centered tetragonal), rhombohedral, hexagonal, orcubic (e.g., simple cubic, body-centered cubic or face-centered cubic).By way of example, the first phase, the second phase, and the thirdphase may each independently include or consist essentially of crystalshaving bravais lattices that are hexagonal, simple cubic, body-centeredcubic, and face-centered cubic, or any combination thereof. The one ormore second phases may include crystals having a bravais lattice that isthe same or different from the bravais lattice of the one or more firstphases. By way of example, the first phase may include a phase having abody-centered cubic bravais lattice, and the second phase may include aphase having a body-centered cubic bravais lattice, a hexagonal bravaislattice, or both. The one or more third phases may include crystalshaving a bravais lattice that is the same as or different from the oneor more first phases, that is different from the one or more secondphases, or any combination thereof. By way of example, the one or morethird phases may include or consist essentially of crystals having abody-centered cubic bravais lattice, a hexagonal bravais lattice, orboth.

FIG. 1 is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, titanium, and tantalum using secondaryelectron imaging. According to the teachings herein, other metalelements may be employed in the sputter target. With reference to FIG.1, the sputter target 10 may include a first phase 16, a second phase14, and a third phase 12. The first phase 16 of the sputter target 10may be a continuous phase, include 50 atomic % or more molybdenum (e.g.,about 75 atomic % or more molybdenum) or both. As illustrated in FIG. 1,the second phase 14, the third phase 12, or both, may be a discretephase (such as a discrete phase dispersed in the first phase). A secondphase, a third phase, or both that is a continuous phase (e.g., aco-continuous phase) is also within the scope of the invention. Thesecond phase 14 may include about 50 atomic % of a second metal elementsuch as titanium, based on the total number of atoms in the secondphase. The third phase 12 may include about 50 atomic % or more of athird element, such as chromium or tantalum, based on the total numberof atoms in the third phase. As illustrated in FIG. 1, the volume of theone or more first phases may be about 40 volume % or more, or about 50volume % or more, based on the total volume of the sputter target. Thevolume of the one or more second phases, the volume or the one or morethird phases, and the total volume of the one or more first and secondphases, may be about 1 volume % or more, or about 5 volume % or more,based on the total volume of the sputter target. The volume of the oneor more second phases, the volume or the one or more third phases, andthe total volume of the one or more first phases and second phases, mayeach be about 50 volume % or less, or about 25 volume % or less, basedon the total volume of the sputter target. The second phase, the thirdphase, or both may be generally randomly oriented. The second phase, thethird phase, or both may be generally elongated. Preferably the secondphase, the third phase, or both, have a length to width ratio of about20:1 or less, about 10:1 or less, or about 5:1 or less. The second phasemay include particles having an average length of about 0.3 μm or more,having an average length of about 200 μm or less, or both. The thirdphase may include particles having an average length of about 0.3 μm ormore, having an average length of about 200 μm or less, or both. Thelength and/or volume of a phase may be measured using scanning electronmicroscopy. Scanning electron microscopy may be supplemented byadditional methods, such as energy dispersive x-ray spectroscopy, formeasuring the composition of a phase.

FIG. 2 is an illustrative scanning electron micrograph of a sputtertarget including molybdenum, niobium and tantalum using backscatteredelectron imaging. According to the teachings herein, other metalelements may be employed in the sputter target. With reference to FIG.2, the sputter target 10 may include a first phase 16, a second phase14, and a third phase 12. Each of the individual phases may be asubstantially pure metallic phase (e.g., a phase that includes a metalin an amount of about 80 atomic % or more, about 90 atomic % or more, orabout 95 atomic % or more). The sputter target may also include an alloyphase, such as an alloy phase including molybdenum and tantalum 18,and/or an intermetallic phase.

The one or more first phases may optionally include both a relativelypure first phase and a highly alloyed first phase containing themolybdenum at a lower concentration than the relatively pure firstphase. For example, the relatively pure first phase may containmolybdenum at a concentration of about 80 atomic % or more, morepreferably about 90 atomic %, or more, based on the total number ofatoms in the relatively pure first phase. By way of example, theconcentration of molybdenum in the highly alloyed first phase may beabout 90 atomic % or less, about 80 atomic % or less, or about 70 atomic% or less. Preferably, the one or more first phases includes asufficient volume of material having a generally high molybdenumconcentration (e.g., about 60 atomic % or more molybdenum, about 70atomic % or more molybdenum, about 80 atomic % or more molybdenum, orabout 90 atomic % or more molybdenum) so that the sputter target can berolled in a step that increases the width, the length, or both, of thesputter target.

The one or more second phases may optionally include both a relativelypure second phase and a highly alloyed second phase containing thetitanium at a lower concentration than the relatively pure second phase.For example, the relatively pure second phase may contain titanium at aconcentration of about 80 atomic % or more, more preferably about 90atomic %, or more, based on the total number of atoms in the relativelypure second phase. By way of example, the concentration of titanium inthe highly alloyed second phase may be about 90 atomic % or less, about80 atomic % or less, or about 70 atomic % or less.

The one or more third phases may optionally include both a relativelypure third phase and a highly alloyed third phase containing the thirdmetal element (e.g., tantalum or chromium) at a lower concentration thanin the relatively pure third phase. For example, the relatively purethird phase may contain the third metal element at a concentration ofabout 80 atomic % or more, more preferably about 90 atomic % or more,based on the total number of atoms in the relatively pure second phase.By way of example, the concentration of the third metal element in thehighly alloyed third phase may be about 90 atomic % or less, about 80atomic % or less, or about 70 atomic % or less.

The volume of the one or more first phases preferably is sufficientlyhigh so that the first phase is a continuous phase (e.g., a matrix phasein which one or more other phases is dispersed). The volume of the oneor more first phases may be about 40% or more by volume, about 50% ormore by volume, about 60% or more by volume, or about 70% or more byvolume, based on the total volume of the sputter target. Preferably thevolume of the one or more first phases is greater than the volume of theone or more second phase. Preferably the volume of the one or more firstphases is greater than the volume of the one or more second phases. Thevolume of the one or more first phases may be about 99% or less byvolume, about 95% or less by volume, about 92% or less by volume, orabout 90% or less by volume, based on the total volume of the sputtertarget.

The volume of the one or more second phases, the one or more thirdphases, or the combination of the one or more second phases and the oneor more third phases may be about 1% or more by volume, about 2% or moreby volume, about 3% or more by volume, or about 5% or more by volume,based on the total volume of the sputter target. The volume of the oneor more second phases, the one or more third phases, or the combinationof the one or more second phases and the one or more third phases may beabout 50% or less by volume, about 45% or less by volume, about 40% orless by volume, about 35% or less by volume, about 30% or less byvolume, about 25% or less by volume, or about 20% or less by volume,based on the total volume of the sputter target.

The one or more first phases, the one or more second phases, and the oneor more third phases of the sputter target may each individually bediscrete phases, continuous phases, or co-continuous phases. Preferably,the sputter target may include a first phase that is a continuous phase.Without being bound by theory, it is believed that a first phase that iscontinuous may improve the capability of rolling a sputter target inorder to increase its length, increase its width, or both. Preferablythe one or more second phases includes a discrete second phase. Forexample, a discrete second phase may be a discrete phase within thefirst phase, or a discrete phase within the third phase. Morepreferably, the sputter target includes a second phase including 50atomic or more titanium that is a discrete phase within a first phaseincluding 50 atomic % or more molybdenum. Preferably, the one or morethird phases includes a discrete phase. For example a discrete thirdphase may be a discrete phase within the first phase, or a discretephase within the second phase. Preferably, the sputter target includes athird phase including 50 atomic % or more of chromium or tantalum thatis a discrete phase within a first phase including 50 atomic % or moremolybdenum. If the sputter target has at least two second phases, it mayhave a morphology in which one of the second phases contains about 80atomic % or more titanium and is encapsulated by another of the secondphases that contains a lower concentration of the second metal element.If the sputter target has at least two third phases, it may have amorphology in which one of the third phases contains about 80 atomic %or more of the third metal element and is encapsulated by another of thethird phases that contains a lower concentration of the third metalelement.

The size of the domains (i.e., a contiguous region that may include oneor more grains of a phase) of one or more, or even all of the phases ofthe sputter target may be relatively large. For example, the size of thedomains of the one or more, or even all of the phases of the sputtertarget may be larger (e.g., by 50% or more, by about 100% or more, byabout 200% or more, by about 500% or more, or by about 1000% or more)than the size of the domains of the phase or phases of a deposited layerprepared from the sputter target. Without limitation the domain size(e.g., the number average length of the domains) of the one or morefirst phases, the one or more second phases, and/or the one or morethird phases, may be about 0.3 μm or more, preferably about 0.5 μm ormore, more preferably about 1 μm or more, and most preferably greater 3μm or more. In determining the domain sizes of the phases of the sputtertarget, all of the first phases may be considered as one phase, all ofthe second phases may be considered as one phase, and all of the thirdphases may be considered as one phase. Without limitation the domainsize (e.g., the number average length of the domains) of the one or morefirst phases, of the one or more second phases, and/or the one or morethird phases, may be about 200 μm or less, preferably about 100 μm orless, and more preferably about 50 μm or less. It will be appreciatedthat larger domain sizes may be employed in the sputter target. Forexample, as taught herein, one or more of the phases may be a continuousphase. The shape of the domains of the second phase, the third phase, orboth may be generally elongated. Preferably the second phase, the thirdphase, or both, have a length to width ratio of about 20:1 or less,about 10:1 or less, or about 5:1 or less.

FIG. 3A is a scanning electron micrograph (backscattered electrons) of aregion of a sputter target including molybdenum, titanium and tantalumincluding a molybdenum phase 16 and illustrating a location 32 in themolybdenum phase. FIG. 3B is an illustrative energy dispersive x-rayspectrograph 30 taken at location 32 of FIG. 3A. The spectrograph ofFIG. 3B includes only a peak 34 corresponding to molybdenum. Asillustrated by FIG. 3B, the sputter target may include a region thatincludes a phase of substantially pure molybdenum (i.e., including about80 atomic % or more molybdenum, about 90 atomic % or more molybdenum, orabout 95 atomic % or more molybdenum).

FIG. 4A is a scanning electron micrograph (backscattered electrons) of aregion of a sputter target including molybdenum, titanium and tantalumincluding a titanium phase 14 and a location 42 in the titanium phase.FIG. 4B is an illustrative energy dispersive x-ray spectrograph taken atthe point 42 of FIG. 4A. The spectrum 40 of FIG. 4B includes only peaks44, 44″, and 44″ corresponding to titanium. As illustrated by FIG. 4B,the sputter target may include a region that includes a phase ofsubstantially pure titanium (i.e., including about 80 atomic % or moretitanium, about 90 atomic % or more titanium, or about 95 atomic % ormore titanium).

FIG. 5A is a scanning electron micrograph (backscattered electrons) of aregion of a sputter target including molybdenum, titanium and tantalumincluding a tantalum phase 12, a molybdenum phase 16, and a location 52in the tantalum phase. FIG. 5B is an illustrative energy dispersivex-ray spectrograph taken at location 52 of FIG. 5A. The spectrum 50 ofFIG. 5B includes only peaks 54, 54′, 54″, and 54″′ corresponding totantalum. As illustrated by FIG. 5B, the sputter target may include aregion that includes a phase of substantially pure third metal element,such as a phase of substantially pure tantalum (i.e., including about 80atomic % or more tantalum, about 90 atomic % or more tantalum, or about95 atomic % or more tantalum), or substantially pure chromium (i.e.,including about 80 atomic % or more chromium, about 90 atomic % or morechromium, or about 95 atomic % or more chromium).

Molybdenum Concentration of the Sputter Target

The total concentration of molybdenum in the target may be at leastabout 50 atomic %, preferably at least about 60 atomic %, morepreferably at least about 65 atomic %, even more preferably at leastabout 70 atomic %, and most preferably at least about 75 atomic %. Theconcentration of molybdenum in the target may be less than about 95atomic %, preferably less than about 90 atomic %, more preferably lessthan about 85 atomic %, even more preferably less than about 83 atomic%, and most preferably less than about 81 atomic %. The sputter targetpreferably is prepared using a process that includes a step of rollingthe material to form the sputter target. As such, the sputter targetpreferably includes a sufficient quantity of molybdenum so that thematerial can undergo a rolling step, such as a rolling step describedhereinafter.

Additional Elements:

In addition the molybdenum, the target includes at least two additionalmetal elements (i.e., a second metal element and a third metal element).The second metal element and the third metal element may eachindependently have an atomic mass greater than or less than the atomicmass of molybdenum. For example, the second metal element may have anatomic mass that is less than the atomic mass of molybdenum and thethird metal element may have an atomic mass that is greater than theatomic mass of molybdenum. As another example, the second metal elementand the third metal element may bath have an atomic mass less than theatomic mass of molybdenum. The second and third metal elements may beselected from IUPAC group 4, 5, and 6 elements. Preferably the targetincludes two or more elements, the second metal element and the thirdmetal element) selected from the group consisting of titanium, tantalum,chromium, hafnium, zirconium, and tungsten. More preferably the targetincludes two or more elements selected from the group consisting oftitanium, tantalum, and chromium. Preferably the second metal element ofthe sputter target is titanium. Preferably, the third metal element ofthe sputter target is tantalum or chromium.

Without limitation, exemplary targets include targets including,consisting essentially of, or consisting of: molybdenum, titanium, andtantalum; molybdenum, titanium, and chromium; molybdenum, tantalum, andchromium, or molybdenum, titanium, tantalum and chromium.

The concentration of the second metal element, the third metal element,or the combination of the second and third metal element in the sputtertarget may be about 0.1 atomic % or more, preferably about 0.5 atomic %or more, more preferably about 1 atomic % or more, even more preferablyabout 2 atomic % or more, and most preferably about 5 atomic % or more,based on the total concentration of atoms in the target. Theconcentration of the second metal element, the third metal element, orthe combination of the second and third metal element in the sputtertarget may be less than about 50 atomic %, preferably about 45 atomic %or less, more preferably about 40 atomic % or less, even more preferablyabout 35 atomic % or less and most preferably about 30 atomic % or less,based on the total concentration of atoms in the target.

The theoretical density of the sputter target, ρ_(t), may be calculatedby the densities of the individual elements:ρ_(t)=[(C ₁ W ₁)+(C ₂ W ₂)+(C ₃ W ₃)]/[(C ₁ W ₁/ρ₁)+(C ₂ W ₂/ρ₂)+(C ₃ W₃/ρ₃)]where C₁, C₂, C₃ are the concentrations (in atomic %) of molybdenum, thesecond metal element and the third metal element, respectively, W₁, W₂,W₃ are the atomic masses of molybdenum, the second metal element and thethird metal element, respectively, and ρ₁, ρ₂, ρ₃ are the densities ofmolybdenum, the second metal element and the third metal element. Ingeneral, the theoretical density of a composition including n elementsmay be estimated by:ρ_(t)=[Σ(C _(i) W _(i))]/[Σ(C _(i) W _(i)/ρ_(i))]where the summations are from element i=1 to n, and C_(i), W_(i), andρ_(i) are respectively, the concentration, atomic mass, and density ofelement i.

The density of molybdenum, titanium, vanadium, chromium, niobium, andtantalum are about 10.2, 4.51, 6.11, 7.15, 8.57, and 16.4 g/cm³,respectively. The density of the sputter target may be greater thanabout 0.85 ρ_(t), preferably greater than about 0.90 ρ_(t), morepreferably greater than about 0.92 ρ_(t), even more preferably greaterthan about 0.94 ρ_(t), even more preferably greater than about 0.96ρ_(t), and most preferably greater than about 0.98 ρ_(t). The density ofthe sputter target is preferably less than about 1.00 ρ_(t).

Texture of the Sputter Target

The texture of a sputter target may be determined by the orientation ofthe grains, such as the orientation of the grains of the first phase,the second phase, the third phase, or any combination thereof. Forexample, one or more of the phases may generally be oriented with<110>//ND, <111>//ND, <100>//ND, or a combination thereof. The rates atwhich the sputter target is sputtered (e.g., the deposition rate of asputtered film) may depend on the orientation of the grains. As such, insome aspects of the invention, the sputter target has a generallyuniform orientation. The orientation of the grains may be measured byelectron back scattered diffraction, using the method described in U.S.Patent Application Publication No. 2008/0271779A1 (Miller et al.,published Nov. 6, 2008) and International Patent Application PublicationNo. WO 2009/020619 A1 (Bozkaya et al., published Feb. 12, 2009), thecontents of which are both incorporated herein by reference in theirentirety. Thus measured, in a unit volume of a face centered cubic metalthe percentage of grains aligned within 15-degrees of <100>//ND may begreater than about 5%, greater than about 8%, greater than about 10.2%,greater than about 13%, or greater than about 15%, the percentage ofgrains aligned within 15-degrees of <111>//ND may be greater than about5%, greater than about 10%, greater than about 13.6%, or greater thanabout 15%, or greater than about 18%, or any combination thereof. Thusmeasured, the percentage of grains in a unit volume of a body centeredcubic metal aligned within 15 degrees of <110>//ND may be greater thanabout 5%, greater than about 15%, 20.4%, or greater than about 30%. Thestandard deviation of the texture gradient (e.g., the 100 gradient, the111 gradient, or both) may be less than about 4.0, preferably less thanabout 2.0, more preferably less than about 1.7, even more preferablyless than about 1.5, and even more preferably less than about 1.3. andmost preferably less than about 1.1.

The variation in the orientation in the through-thickness direction mayalso be relatively low. For example, through-thickness texture gradientfor the texture components 100//ND, 111//ND, or both may be 6%/mm orless, preferably 4%/mm or less, and more preferably 2%/mm or less (asmeasured using the method described in International Patent ApplicationPublication No. WO 2009/020619 A1).

Deposited Molybdenum Containing Layer

As previously described, the sputter targets may be used to produce astructure having at least one molybdenum containing layer (e.g., adeposited layer, such as a deposited film layer) that comprisesmolybdenum, a second metal element, and a third metal element. Forexample, the sputter target may be used to produce a deposited layercomprising molybdenum, titanium, and a third metal element selected fromthe group consisting of chromium and tantalum. Preferably the thirdmetal element is tantalum. The process of depositing a molybdenumcontaining layer on a substrate may include one or any combination ofthe following: providing a particle, such as a charged particle,accelerating a particle, or impacting a sputter target with a particle,so that atoms are removed from a sputter target and deposited onto asubstrate. Preferred particles include atomic particles and subatomicparticles. By way of example, the subatomic particle may be an ion.Preferably, the molybdenum containing layer includes about 50 atomic %or more molybdenum, about 0.5 atomic % or more titanium, and about 0.5atomic % or more tantalum, based on the total number of atoms in thelayer. The concentration of molybdenum in the molybdenum containinglayer may be about 60 atomic % or more, about 65 atomic % or more, about70 atomic % or more, or about 75 atomic % or more, based on the totalconcentration of atoms in the molybdenum containing layer. Theconcentration of molybdenum in the molybdenum containing layer may beabout 98 atomic % or less, preferably about 95 atomic % or less, morepreferably about 90 atomic % or less, even more preferably about 85atomic % or less, and most preferably about 83 atomic % or less, basedon the total number of atoms in the molybdenum containing layer. Theratio of the concentration of molybdenum (in atomic %) in the depositedlayer to the concentration of molybdenum in the sputter target (inatomic %) may be about 0.50 or more, about 0.67 or more, about 0.75 ormore, about 0.80 or more, or about 0.9 or more. The ratio of theconcentration of molybdenum in the deposited layer to the concentrationof molybdenum in the sputter target may be about 2.00 or less, about 1.5or less, about 1.33 or less, about 1.25 or less, or about 1.11 or less.

The second metal element and the third metal element may eachindependently be present at a concentration greater than about 0.1atomic %, preferably greater than about 1 atomic %, more preferablygreater than about 3 atomic %, even more preferably greater than about 5atomic % and most preferably greater than about 7 atomic %, based on thetotal concentration of atoms in the molybdenum containing layer. Thesecond metal element and the third metal element may each independentlybe present at a concentration of about 45 atomic % or less, about 40atomic % or less, about 35 atomic % or less, about 30 atomic % or less,about 25 atomic % or less, about 20 atomic % or less, or about 10 atomic% or less, based on the total concentration of atoms in the molybdenumcontaining layer.

The total concentration of the second and third metal elements ispreferably about 5 atomic % or more, more preferably about 10 atomic %or more, and most preferably about 15 atomic % or more, based on thetotal concentration of atoms in the molybdenum containing layer. By wayof example, the total concentration of the second and third metalelements may be about 20 atomic % or more, based on the totalconcentration of atoms in the molybdenum containing layer. The total ofthe second metal element and the third metal element may be about 50atomic % or less, about 45 atomic % or less, about 40 atomic % or less,about 35 atomic % or less, about 30 atomic % or less, or about 25 atomic% or less, based on the total concentration of atoms in the molybdenumcontaining layer. The ratio of the total concentration of the second andthird metal elements (in atomic %) in the deposited layer to the totalconcentration of the second and third metal elements in the sputtertarget (in atomic %) may be about 0.50 or more, about 0.67 or more,about 0.8 or more, or about 0.9 or more. The ratio of the totalconcentration of the second and third metal elements (in atomic %) inthe deposit layer to the total concentration of the second and thirdmetal elements in the sputter target (in atomic %) may be about 2.00 orless, about 1.5 or less, about 1.25 or less, or about 1.11 or less.

The deposited molybdenum containing layer may be deposited (e.g., by aprocess that includes a step of sputtering the sputter target) onto asubstrate. For example, the sputter target may be employed in a processfor producing a multi-layered article including a molybdenum containinglayer (e.g., a deposited layer) including a first phase of themolybdenum containing layer having about 50 atomic % or more molybdenum,about 0.1 atomic % or more titanium and about 0.1 atomic % or more ofthe third metal element, wherein the third metal element is chromium ortantalum. The first phase of the molybdenum containing layer maycomprise 60 volume % or more, 70 volume % or more, 80 volume % or more,90 volume % or more, or 95 volume % or more of the molybdenum containinglayer. The molybdenum containing layer may be substantially entirely thefirst phase of the deposited layer. The concentration of the molybdenum,the second metal element, and the third metal element in the first phaseof the deposited molybdenum containing layer may be any of the abovedescribed concentrations for the molybdenum, the second metal element,and the third metal element in the molybdenum containing layer.

The deposited molybdenum containing layer may have a grain size of about5 to 10,000 nm. The average grain size may be measured using microscopy(e.g., scanning electron microscopy) of a surface normal to thethickness of the deposited layer. The size of an individual grain may betaken as the largest dimension of the grain in the plane normal to thethickness of the deposited layer. The deposited molybdenum containinglayer (e.g., the first phase of the deposited layer) preferably has arelatively small grain size (e.g., a grain size less than the grain sizeof the first phase of the sputter target, the second phase of thesputter target, the third phase of the sputter target, or anycombination thereof). The first phase of the deposited molybdenumcontaining layer may have a grain size of about 5 nm or more, about 10nm or more, about 20 nm or more, or about 50 nm or more. The first phaseof the deposited molybdenum containing layer may have a grain size ofabout 10,000 nm or less. Preferably, the first phase of the depositedfilm layer has a grain size of about 1000 nm or less, about 500 nm orless, about 200 nm or less, or about 150 nm or less. The grains may begenerally randomly oriented, the grains may be generally aligned, or anycombination thereof. The grains may have any shape. For example, thegrains may be generally elongated. Preferably, the grains have a lengthto width ratio that is less than about 100:1, more preferably less thanabout 30:1, and most preferably less than about 10:1. The depositedlayer may include grains that have a generally large length to widthratio (e.g., greater than about 5:1 and grains that have a generallysmall length to width ratio (e.g., less than about 5:1, or less thanabout 2:1). The grains may have a generally uniform shape, such as ashape having a length to width ratio less than about 3:1, less thanabout 2:1, or less than about 1.5:1.

By way of example, FIG. 6A illustrates (without limitation) amicrostructure using secondary electron scanning electron microscopy ata magnification of about 50,000 of a deposited layer containing about 80atomic % molybdenum, about 10 atomic titanium, and about 10 atomic %tantalum. With reference to FIG. 6A, the deposited molybdenum containinglayer may be substantially a single phase.

The thickness of the deposited molybdenum containing layer may varydepending on the functional requirements of the deposited layer. Withoutlimitation, the thickness of the deposited layer may be about 1 nm ormore, about 5 nm or more, about 10 nm or more, about 15 nm or more,about 20 nm or more, about 25 nm or more, about 30 nm or more, or about35 nm or more. The thickness of the deposited molybdenum containinglayer may be about 3 μm or less. Preferably, the thickness of thedeposited molybdenum containing layer is about 1 μm or less, morepreferably about 0.5 μm or less, even more preferably about 0.2 μm orless, even more preferably about 100 nm or less, and most preferablyabout 50 nm or less. Deposited layers having a thickness less than about1 nm are also contemplated.

FIG. 7 is a secondary electron scanning electron microscope micrograph(at a magnification of about 10,000) of the cross-section of a depositedlayer 70 containing about 80 atomic % molybdenum, 10 atomic % titanium,and about 10 atomic % tantalum on a substrate 72. As illustrated in FIG.7, the deposited layer may include a generally columnar microstructure.Other microstructures are also contemplated.

The arrangement of the atoms in the deposited molybdenum containinglayer may be different from the arrangement of the atoms in the sputtertarget. For example, the deposited layer may include one or more firstalloy phases comprising i) at least 50 atomic % molybdenum and ii) atleast one of the second metal element and the third metal element. Thedeposited layer may be substantially free of (e.g., contain less than 30volume %, more preferably less than about 10 volume %, and mostpreferably less than about 5 volume %, based on the total volume of thedeposited layer) of phases comprising greater than about 90 atomic %molybdenum. Preferably, a majority of the second metal element in thedeposited layer is present in the one or more first alloy phases.Preferably, a majority or the third metal element in the deposited layeris present in the one or more first alloy phases.

Without limitation, the deposited layer may include one or more firstalloy phases that contains about 70% or more of the molybdenum in thedeposited layer, preferably about 80% or more of the molybdenum in thedeposited layer, more preferably about 90% or more of the molybdenum inthe deposited layer, and most preferably about 95% or more of themolybdenum in the deposited layer. Without limitation, the depositedlayer may include one or more first alloy phases that further containsabout 70% or more of the titanium in the deposited layer, preferablyabout 80% or more of the titanium in the deposited layer, morepreferably about 90% or more of the titanium in the deposited layer, andmost preferably about 95% or more of the titanium in the depositedlayer. Without limitation, the deposited layer may include one or morefirst alloy phases that further contains about 70% or more of the thirdmetal element in the deposited layer, preferably about 80% or more ofthe third metal element in the deposited layer, more preferably about90% or more of the third metal element in the deposited layer, and mostpreferably about 95% or more of the third metal element in the depositedlayer.

Optionally, the deposited layer may contain one or more second alloyphases, each containing less 50 atomic % molybdenum. If present, suchoptional second alloy phases preferably are present in total at aconcentration less than about 40 volume %, more preferably less thanabout 20 volume %, and most preferably less than about 10 volume %,based on the total volume of the deposited layer. Without limitation,the one or more second alloy phase, if present, may each include atleast 50 atomic % of the second metal, at least 50 atomic % of the thirdmetal element, at least 50 atomic % of the second metal and third metal,or any combination thereof.

The deposited layer may be deposited onto a substrate using a physicalvapor deposition process, such as a sputter deposition process (i.e., bysputtering). The deposition process may employ electric fields and/ormagnetic fields (preferably both) to remove atoms or groups of atomsfrom the sputter target using a gas (preferably an inert gas, such asargon) and to deposit at least a portion of the removed atoms onto asubstrate. The deposition process may employ one or more steps ofheating a sputter target, one or more steps of etching a sputter targetand/or substrate (for example to remove an oxide layer), one or moresteps of cleaning a sputter target and/or substrate, or any combinationthereof. The sputtering may be performed in a vacuum chamber at apressure less than atmospheric pressure. The pressure, temperature, andelectric fields may be chosen so that a plasma is formed. By way ofexample, the process may include sputtering at one or more pressures ofabout 100 Torr or less (about 13.3 kPa or less), preferably about 1000mTorr or less (about 133 Pa or less), more preferably about 100 mTorr orless (about 13.3 Pa or less), and most preferably about 20 mTorr or less(about 2.67 Pa or less). The process preferably includes sputtering atone or more pressures of about 0.1 mTorr or more (about 0.0133 Pa ormore), preferably about 1 mTorr or more (about 0.133 Pa or more), andmore preferably about 2 mTorr or more (about 0.267 Pa or more).

Without limitation, the deposited molybdenum containing layer mayfunction as a barrier layer, such as for performing the function ofsubstantially or entirely avoiding the migration of atoms of anunderlying layer into an overlying layer, substantially or entirelyavoiding the migration of atoms of an overlying layer into an underlyinglayer, or both. For example, the deposited molybdenum containing layermay be deposited over a first material (e.g., a first substratematerial) and then have a second material deposited over it. As such,the deposited molybdenum containing layer may prevent the migration(e.g., during an annealing step, during a forming step, or during use)of the one or more components of the first material into the secondmaterial, one or more components of the second material into the firstmaterial, or both. The molybdenum containing layer may be interposedbetween a substrate (e.g., a silicon substrate, or a glass substrate)and a conductive layer (such as a layer containing or consistingessentially of Cu, Al, Ag, Au, or any combination thereof). Thethickness of the deposited molybdenum containing layer (e.g., employedas a barrier layer) may be about 1000 nm or less, about 500 nm or less,about 200 nm or less, about 100 nm or less, or about 50 nm or less. Thethickness of the deposited molybdenum containing layer (e.g., employedas a barrier layer) may be about 1 nm or more. The molybdenum containinglayer may include about 50 atomic % or more molybdenum (e.g., about 80atomic % molybdenum), about 1 atomic % or more titanium (e.g., about 5atomic titanium), and about 1 atomic % or more of the third metalelement (e.g., about 5 atomic % or more tantalum).

The materials may then be annealed, e.g., using an annealing temperatureof about 350° C. and an annealing time of about 30 minutes to determinethe barrier properties of the molybdenum containing layer. Themolybdenum containing layer may advantageously substantially if notentirely avoid the migration of components of the substrate layer intothe conductive layer and/or the molybdenum containing layer, reduce orprevent the migration of components of the conductive layer into thesubstrate layer and/or the molybdenum containing layer, or anycombination thereof. Without limitation, the molybdenum containing layermay advantageously reduce or prevent the formation of copper silicideafter annealing for about 30 minutes at about 350° C. For example, theconcentration of copper silicide may be below the level detectable byx-ray diffraction methods after annealing for about 30 minutes at about350° C. The deposited molybdenum containing layer may be employed toavoid changes in the electrical resistivity of the deposited layers(e.g., each layer, or the combination of the deposited layers) by anannealing process. Preferably the electrical resistivity changes by lessthan about 30%, more preferably by less than about 20%, and mostpreferably by less than 10%, after annealing for about 30 minutes at about 350° C. Such a generally constant electrical resistivity mayindicate that the molybdenum containing layer is preventing theformation of a silicide, such as copper silicide. The deposited layermay avoid the migration of copper atoms into a silicon layer, migrationof silicon atoms into a copper layer, or both. For example theconcentration of copper atoms at the surface of the silicon layer may beless than 1 atomic %, preferably less than about 0.1 atomic % and mostpreferably below the limit of detection as measured by Augerspectroscopy after annealing a structure comprising a deposition layerincluding molybdenum, the second metal element and the third metalelement on a clean silicon wafer, deposited by sputtering the sputtertarget using a magnetron, the deposition layer having a thickness ofabout 25 nm, and a layer of copper deposited over the deposition layer,the annealing at a temperature of about 350° C. and a time of about 30minutes. Under the same conditions, the concentration of silicon atomsat the surface of the copper layer may be about 1 atomic % or less,preferably about 0.1 atomic % or less, and most preferably below thelimit of detection as measured by Auger spectroscopy.

By way of illustration, FIG. 8A illustrates (without limitation) theAuger depth profile of a silicon substrate with a deposited molybdenumcontaining layer and a conductive copper layer. As illustrated in FIG.8A, the molybdenum containing layer may include about 50 atomic % ormore molybdenum (e.g., about 80 atomic % molybdenum), about 1 atomic %or more titanium (e.g., about 5 atomic titanium), and about 1 atomic %or more of the third metal element (e.g., about 5 atomic % or moretantalum). The materials may then be annealed, e.g., using an annealingtemperature of about 350° C. and an annealing time of about 30 minutesto determine the barrier properties of the molybdenum containing layer.As illustrated in FIG. 8B, the molybdenum containing layer mayadvantageously substantially if not entirely avoid the migration ofsilicon atoms from the substrate layer into the conductive layer and/orthe molybdenum containing layer, reduce or prevent the migration ofcopper atoms from the conductive layer into the substrate layer and/orthe molybdenum containing layer, or any combination thereof. Withoutlimitation, the molybdenum containing layer may advantageously reduce orprevent the formation of copper silicide after annealing for about 30minutes at about 350° C.

The deposited molybdenum containing layer may be characterized by one orany combination of the following: a generally good adhesion to glass(e.g., at least 2B, at least 3 B, at least 4 B, or at least 5 B ratingwhen tested according to ASTM B905-00), a generally good adhesion tosilicon (e.g., at least 2 B, at least 3 B, at least 4 B, or at least 5 Brating when tested according to ASTM B905-00), a generally good adhesion(e.g., at least 2 B, at least 3 B, at least 4 B, or at least 5 B ratingwhen tested according to ASTM B905-00) to a conductive layer, such as alayer containing or consisting essentially of copper, aluminum,chromium, or any combination thereof ability to prevent copper silicideformation when the molybdenum containing deposited layer (e.g., having athickness of about 200 nm or less, preferably having a thickness ofabout 35 nm or less, and more preferably having a thickness of about 25nm or less, ability to prevent copper silicide formation when themolybdenum containing deposited layer (e.g., having a thickness of about200 nm or less, preferably having a thickness of about 35 nm or less,and more preferably having a thickness of about 25 nm or less) is placedbetween and in contact with Si and Cu and annealed for about 30 minutesat about 350° C.; or an electrical resistivity less than about 60,preferably less than about 45, more preferably less than about 35 μΩ·cmfor a film having a thickness of about 200 nm.

The deposited molybdenum containing layer may have a relatively lowelectrical resistivity. For example, the electrical resistivity of themolybdenum containing layer may be less than the electrical resistivityof a deposited layer of the same thickness consisting of 50 atomic %molybdenum and 50 atomic % titanium.

Preferably the deposited molybdenum containing layer has a generally lowelectrical resistivity. For example, the electrically resistivity (asmeasured by a four-point probe on a film having a thickness of about 200nm) of the deposited molybdenum containing layer preferably is of about75 μΩ·cm or less, more preferably about 60 μΩ·cm or less, even morepreferably about 50 μΩ·cm or less, even more preferably about 40 μΩ·cmor less, even more preferably about 30 μΩ·cm or less, and mostpreferably about 28 μΩ·cm or less. Preferably, the electricallyresistivity of the deposited molybdenum containing layer is about 5μΩ·cm or more. It will be appreciated that the electrical resistivity ofthe deposited molybdenum containing layer may also be less than about 5μΩ·cm. The deposited molybdenum containing layer preferably has agenerally uniform electrical resistivity. For example the ratio of thestandard deviation of the electrical resistivity to the averageelectrical resistivity (measured on a 200 nm thick layer deposited on a76.2 mm diameter silicon wafer) preferably is about 0.25 or less, morepreferably about 0.20 or less and most preferably about 0.18 or less.

Etching of the Deposited Molybdenum Containing Layer

After depositing the molybdenum containing layer it may be desirable toat least partially etch the molybdenum containing layer. By way ofexample, a step of etching may be employed so that a portion of themulti-layered structure is etched. It may be desirable for the etch rateof the molybdenum containing layer to be generally low so that at leasta portion of the molybdenum containing layer is not etched, so thatstronger etching chemicals can be employed, so that thinner molybdenumcontaining layers may be employed, or any combination thereof.

The step of etching may include a step of etching with a chemical orsolution capable of removing some or all of the deposited molybdenumcontaining layer. More preferably, the etching step includessufficiently etching the molybdenum layer so that a layer below themolybdenum layer, such as a substrate layer, is at least partiallyexposed after the etching step. The etching step may employ a solutionor chemical that includes an acid. For example, the etching step mayemploy a solution or chemical having a pH of about 8 or more, a pH ofabout 10 or more, or a pH of about 12 or more. The etching step mayemploy a solution or chemical that includes a base. For example, theetching step may employ a solution or chemical having a pH of about 6 orless, a pH of about 4 or less, or a pH of about 2 or less. The etchingstep may employ a solution or chemical that is generally neutral.Generally neutral solutions or chemicals have a pH greater than about 6,a pH of about 6.5 or more, a pH or about 6.8 or more, or a pH of about 7or more. Generally neutral solutions or chemicals also have a pH lessthan about 8, a pH of about 7.5 or less, a pH or about 7.2 or less, or apH of about 7 or less.

The etching process may employ one or more acids. Exemplary acids thatmay be used include nitric acid, sulfuric acid, hydrochloric acid, andcombinations thereof. The etching process may employ a sulfate.Exemplary sulfates include those described in U.S. Pat. No. 5,518,131,column 2, lines 3-46 and column 2, lines 62 to column 5, line 54,expressly incorporated herein by reference, such as ferric sulfate andferric ammonium sulfate. The etching process may employ a solutionincluding ferricyanide ions, chromate ions, dichromate ions, ferricions, or any combination thereof. For example, the etching process mayemploy one or more ions containing solutions described in U.S. Pat. No.4,747,907, column 1, line 66 to column 8, line 2, incorporated byreference herein. A particularly preferred solution for etching themolybdenum containing layer is a solution including ferricyanide ions.

Preferably, the process of preparing the multi-layered structureincludes a step of etching the molybdenum containing layer at a rate ofabout 100 nm/min or less, more preferably about 70 nm/min or less, evenmore preferably about 60 nm/min or less, even more preferably about 50nm/min or less, even more preferably about 40 nm/min or less, and mostpreferably about 30 nm/min or less. The etching step may employ anyetching solution capable of etching the one or more layers of themulti-layered structure. The etching step may employ a ferricyanidesolution at one or more of the above rates.

The deposited molybdenum containing layer may have a relatively low etchrate in ferricyanide solution at 25° C., such as an etch rate lower thanthe etch rate of a deposited layer consisting of 50 atomic % molybdenumand 50 atomic % titanium using the same etching conditions. The etchrate of the molybdenum containing layer in ferricyanide solution at 25°C. is preferably about 100 nm/min or less, more preferably about 70nm/min, even more preferably about 60 nm/min or less, even morepreferably about 50 nm/min or less, even more preferably about 40 nm orless, and most preferably about 30 nm/min or less. The etch rate of themolybdenum containing layer in ferricyanide solution at 25° C. ispreferably about 0.1 nm/min or more.

Process

In general, the targets (or preformed structures, such as blocks forassembling into a target) may be made using metal powder startingmaterials. One such approach includes consolidating such powders, suchas by heat, pressure, or both. For example, powders may be compacted andsintered, cold isostatically pressed, hot isostatically pressed, or anycombination thereof.

The process for making the target may include one or any combination ofthe steps disclosed by Gaydos et al. in U.S. Patent ApplicationPublication Nos. 2007/0089984A1, published on Apr. 26, 2007 andUS2008/0314737, published on Dec. 25, 2008, the contents of which areincorporated herein by reference in their entirety.

The process for making the sputter targets may include a step ofproviding at least a first powder including at least 50 atomic %molybdenum, a second powder including at least 50 atomic % of a secondmetal element, and a third powder including at least 50 atomic % of athird metal element. For example, the process for making the targets mayinclude a step of providing a first powder including at least 50 atomic% molybdenum, a step of providing a second powder including at least 50atomic % titanium, a step of providing a third powder including at least50 atomic % of tantalum or chromium, or any combination thereof. Theindividual powders (e.g., the first powder, the second powder and thethird powder) may be blended together to produce a blended powder. Theblending step preferably uses a temperature sufficiently low so thatpowder does not fuse together. The blending preferably uses a sufficientblending time and speed so that the first powder, the second powder, andthe third powder become generally randomly distributed. By way ofexample, the blending may be performed at a temperature below about 100°C. (e.g., at about 25° C.) in a V-blender.

Preferably the process of preparing the sputter target is free of a stepof mixing (e.g., mechanically mixing) two or more of the first powder,the second powder, and the third powder at a temperature at which analloy is formed. For example, the process may be free of a step ofmixing two or more of the first powder, the second powder, and the thirdpowder at a temperature of about 550° C. or more, about 700° C. or more,about 900° C. or more, about 1100° C. or more, about 1200° C. or more,or about 1500° C. or more.

The process may optionally include one or more steps of consolidatingthe blended powder to produce a consolidated powder. The process mayinclude one or more steps of encapsulating the blend powder or theconsolidated powder to produce an encapsulated powder and/or one or moresteps of compacting while heating the encapsulated powder to produce afirst target plate.

Preferably, the process of preparing the sputter target includes one ormore steps of pressing the powders or the consolidated powders to form atarget plate (e.g., a block or blank) by pressing at a predeterminedtime, at a predetermined pressing pressure, and for a predeterminedpressing temperature sufficiently high so that the powders fuse togetherand/or so that the density of the material increases to at about 0.85ρ_(t) or more, where ρ_(t) is the theoretical density. The target plate(e.g., the block or blank) may be further processed (e.g., as describedhereinafter) to form a sputter target. As such, it will be recognizedthat target plates and methods for producing target plates are includedin the teachings herein. Various compacting methods are known in theart, including, but not limited to, methods such as inert gas uniaxialhot pressing, vacuum hot pressing, and hot isostatic pressing, and rapidomnidirectional compaction, the Ceracon™ process. The pressing steppreferably includes a step of hot isostatically pressing the powder.Preferably the predetermined temperature is about 800° C. or more, morepreferably about 900° C. or more, even more preferably about 1000° C. ormore, even more preferably about 1100° C. or more, and most preferablyabout 1200° C. or more. Preferably the predetermined temperature isabout 1700° C. or less, more preferably about 1600° C. or less, evenmore preferably about 1500° C. or less, even more preferably about 1400°C. or less, and most preferably about 1300° C. or less. Thepredetermined pressing time may be about 1 minute or more, preferablyabout 15 minutes or more, and more preferably about 30 minutes or more.the predetermined time preferably is about 24 hours or less, morepreferably about 12 hours or less, even more preferably about 8 hours orless, and most preferably about 5 hours or less. The predeterminedpressing pressure may be about 5 MPa or more, about 20 MPa or more,about 50 MPa or more, or about 70 MPa or more. The predeterminedpressure may be about 1000 MPa or less, preferably about 700 MPa orless, more preferably about 400 MPa or less and most preferably about250 MPa or less.

The process for making a target may optionally include a step of bonding(e.g., edge bonding) two or more target plates (e.g., a first targetplate and a second target plate) to produce a bonded target plate. Thebonding process may be a diffusion bonding process. The bonding processmay be a diffusion bonding process. Such a bonding may be advantageousin producing targets having a relatively large area (e.g., a lengthgreater than about 67 inches (1702 mm), or greater than about 84 inches(2134 mm) and a width greater than about 55 inches (1397 mm), or greaterthan about 70 inches (1778 mm).

As taught herein, in a preferred aspect of the invention, a target plateformed by pressing may be capable of being rolled so that the length ofthe target plate is increased, so that the width of the target plate isincreased, or both. As such, the process of forming the sputter targetmay be substantially free of, or even entirely free of a step of abonding (e.g. edge bonding) two or more target plates. It will beappreciated that one or more steps of rolling the target plate may beemployed. By rolling the target plate, the need for large molds and/orlarge presses (such as molds and/or presses that are at least about thesize of the final sputter target) may be avoided. One or more steps ofrolling may be advantageous in producing sputter targets having arelatively large area (e.g., a length greater than about 67 inches (1702mm), or greater than about 84 inches (2134 mm) and a width greater thanabout 55 inches (1397 mm), or greater than about 70 inches (1778 mm).

Forging

The process for making the target may optionally include one or moresteps of forging. If employed, the forging step may include hot forging(e.g., at a temperature above a recrystallization temperature of thetarget material). Suitable forging methods that may be used includepress forging, upset forging, automatic hot forging, roll forging,precision forging, induction forging, and any combination thereof.Without limitation, the forging process may employ rotary axial forgingas described for example in International Patent Application PublicationNo. WO2005/108639 A1 (Matera et al., published on Nov. 17, 2005), thecontents of which are incorporated herein by reference in its entirety.A rotary axial forging process may employ a rotary axial forging machinesuch as one described in Paragraph 0032 of WO2005/108639 A1.

Reducing/Eliminating Variation in Texture

The process for making the target may include a step of tilt rolling orother asymmetric rolling, using a method or apparatus such as describedin International Patent Application No. WO 2009/020619 A1 (Bozkaya etal, published on Feb. 12, 2009), the contents of which are incorporatedherein by reference in its entirety.

Applications

The sputter targets may be employed in producing one or more layers(e.g., as one or more barrier layers) in an electrode substrate of aflat panel display or a photovoltaic cell. Examples of flat paneldisplays which may advantageously employ the sputter targets of thepresent invention include a liquid crystal display (e.g., an activematrix liquid crystal display, such as a thin film transistor-liquidcrystal display (i.e., a TFT-LCD)), a light emitting diode, a plasmadisplay panel, a vacuum fluorescent display, a field emission display,an organoluminescent display, an electroluminescent displays, and anelectro-chromic displays.

Devices that may include molybdenum containing films prepared from thesputter targets include computer monitors, optical disks, solar cells,magnetic data storage, optical communications, decorative coatings, hardcoatings, glass coatings including WEB coatings, cameras, videorecorders, video games, cell phones, smartphones, touch screens, globalpositioning satellite devices, video scoreboards, video billboards,other display panels, or the like.

With reference to FIG. 10, one such device may include a multi-layeredstructure 102. The multi-layered structure includes two or more layersincluding a substrate layer 104 and a deposited molybdenum containinglayer 106. The substrate layer may be formed of a glass, asemiconductor, a metal, a polymer, or any combination thereof. It willbe appreciated that the substrate layer may include a plurality ofmaterials. A preferred substrate layers includes or consists essentiallyof glass. Another preferred substrate layer includes or consistsessentially of silicon. The multi-layered structure includes one or moredeposited layers 106. The deposited layer 106 may be formed by a sputtermethod according to the teachings herein, may be formed from a sputtertarget according to the teachings herein, or both. The deposited layer106, may be a thin film. The deposited layer may have a thickness lessthan the thickness of the substrate layer 102. The deposited layer mayhave a thickness less than about 1 μm, even more preferably less thanabout 200 nm, even more preferably less than about 100 nm, and mostpreferably less than about 50 nm. The deposited layer 106 may bedeposited onto the substrate 104, or the deposited layer 106 may bedeposited onto one or more intermediate layers (not shown) interposedbetween the substrate layer 104 and the deposited layer 106. Themulti-layered structure 102 may also include one or more conductivelayers 108. The conductive layer 108 may have an electrical conductivitygreater than the substrate layer 104, greater than the deposited layer106, or preferably greater than both the substrate layer 104 and thedeposited layer 106. The deposited layer 106 preferably is interposedbetween the substrate layer 104 and a conductive layer 108. For example,a deposited layer 106 may include a first surface at least partially incontact with the substrate layer 104, and an opposing surface at leastpartially in contact with a conductive layer 108. As such, the depositedlayer 106 may be a barrier layer that reduces or prevents the diffusionof atoms between a conductive layer 108 and a substrate layer 102.

Test Methods

Adhesion

Adhesion is measured using an adhesion tape test according to ASTM6905-00. A rating of 5 B indicates good adhesion and that the depositedlayer is not removed by the tape.

Deposition Rate

Deposition rate is determined by measuring the thickness of thedeposited layer (in units of nm) and dividing by the deposition time (inunits of minutes).

Etch Rate

The etch rate (in units of μm/min) is measured as the rate of change inthickness of the deposited layer when immersed in a ferricyanidesolution at 25° C. A ferricyanide solution is used.

Electrical Resistivity

The sheet resistance of the deposited films is measured using afour-point probe. Two samples are measured for each depositioncondition. The resistivity is then calculated by the geometry of thetest sample.

Microstructure of deposited films.

The microstructure of the deposited films is obtainable using scanningelectron microscopy. A JEOL JSM-7000F field emission electron microscopethat can measure backscattered electrons and secondary electrons is usedin the examples.

Microstructure of the sputter targets.

The micostructure of the sputter targets is obtainable using scanningelectron microscopy. An ASPEX Personal Scanning Electron Microscope isemployed. The working distance is about 20 mm and the accelerationvoltage is about 20 keV. The secondary electron detector isEverhart-Thornley type. The images are also obtained of thebackscattered electrons. The electron microscope is also employed formeasurement of energy dispersive x-ray spectroscopy using a spot size ofabout 1 μm. Samples for electron microscopy of the sputter target areprepared by sectioning with an abrasive cutoff wheel, mounting thesection in a polymeric material, rough grinding with SiC papers withprogressively finer grits, final polishing with a diamond paste and thenwith an Al₂O₃, SiO₂ suspension.

X-ray Diffractions

X-ray diffraction studies are performed using a Phillips XPert Pro X-raydiffractometer.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner.

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints. The use of “about” or “approximately” inconnection with a range applies to both ends of the range. Thus, “about20 to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of” to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist essentially of orconsist of the elements, ingredients, components or steps.

Plural elements, ingredients, components or steps can be provided by asingle integrated element, ingredient, component or step. Alternatively,a single integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theinvention should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

EXAMPLES Examples 1-10 Molybdenum Titanium/Tantalum

Example 1 illustrates a sputter target including molybdenum, titaniumand tantalum. Examples 2-9 illustrate deposited films prepared from thesputter target of Example 1.

Example 1

Example 1 is a sputter target that is prepared by first blendingmolybdenum powder having a particle size of about 3-4 μm, tantalumpowder having a particle size of about 45-90 μm, and titanium powderhaving a particle size of about 10-45 μm, to form a powder blend havingabout 80 atomic % molybdenum, about 10 atomic % titanium, and about 10atomic % tantalum. The blending is done in a V-blender for about 20minutes to obtain a homogeneous mixture of the three different powders.The resulting powder blend is then consolidated by uniaxially pressingwith an applied force of about 340,000 kg into pellets having a diameterof about 95 mm (i.e., a pressure of about 470 MPa) at a temperature ofabout 23° C. The pressed pellet is then encapsulated in a can made oflow carbon steel and hot isostatically pressed at a temperature of about1325° C. and a pressure of about 100 to about 120 MPa for about 4 hours.Thus prepared, Example 1 has a density which is greater than about 94%of the theoretical density. The consolidated material is then removedfrom the can and machined to a diameter of about 58.4 mm and a thicknessof about 6.4 mm.

The target includes at least one first phase containing greater than 50atomic % molybdenum, at least one second phase containing greater than50 atomic % titanium, and at least one third phase containing greaterthan about 50 atomic % tantalum. A scanning electron micrographs of thesputter target using secondary electrons is illustrated in FIG. 1.Scanning electron micrographs of the sputter target using backscatteredelectrons are illustrated in FIGS. 2, 3A, 4A, and 5A. As illustrated inthese figures, the sputter target may have a morphology including acontinuous phase of molybdenum 16, a discrete phase of tantalum richregions (light regions) 12, and a discrete phase of titanium richregions (dark regions) 14. FIGS. The sputter target is also analyzedusing X-ray absorption spectroscopy for elemental analysis in differentregions of the target. As illustrated in FIG. 3B, the sputter targetincludes a phase consisting essentially of molybdenum. As illustrated inFIG. 4B, the sputter target includes a phase that consists essentiallyof titanium. As illustrated in FIG. 5B, the sputter target includes aregion that consists essentially of tantalum. As illustrated in FIGS.1-5, the majority of the sputter target may be the first phase (i.e.,the phase containing 50 atomic % or more molybdenum) and the first phasemay be a continuous phase.

Near the interfaces between the pure metal phases, there may be alloyphases, such as an alloy phase of molybdenum and titanium, and an alloyphase of molybdenum and tantalum. Without being bound by theory, it isbelieved that an alloy phases (e.g., the molybdenum/titanium alloy phaseand the molybdenum/tantalum alloy phase) in the sputter target may beformed during the hot isostatic pressing step by diffusion of the metalelements (e.g., diffusion of the molybdenum atoms into titanium domainsand into tantalum domains)

Examples 2-9

Examples 2-9 illustrate a method that includes steps of sputtering athin film layer using a sputter target as taught herein onto a substrate(e.g., a silicon-containing substrate, or a glass-containing substrate).Sputtering may be performed using a magnetron. In general, sputteringwill occur for about 1 to about 240 minutes (preferably about 1 to about40 minutes), under conditions of vacuum from about 1 to about 100 mTorrpressure (preferably from about 2 to about 20 mTorr pressure), and aspacing between the substrate and the sputter target of about 5 to 300mm (preferably about 20 to about 150 mm. The resulting structure willhave characteristics consistent with examples 2-9 herein.

Examples 2, 3, 4, 5, 6, 7, 8, and 9 are prepared by placing the sputtertarget of Example 1 into a magnetron sputter deposition chamber usingthe conditions described in Table 1. The substrate is either a siliconwafer (100) orientation, or Corning 1737 glass. Prior to deposition, thesubstrate is cleaned by successive rinsing in ultrasonic baths ofacetone and ethyl alcohol. The substrates are then dried by blowingnitrogen gas. The substrates are next loaded into the deposition chamberalong with the sputter target. The target is sputter cleaned with anargon flow of at a pressure of about 5 mTorr at 200 W DC for about 10minutes. During the cleaning of the target, a shutter is placed in frontof the target to prevent deposition onto the substrate.

When using the glass substrate, the substrate is etched by sputtering at60 mTorr for 30 minutes to remove possible contamination on thesubstrate surface.

After the sputter cleaning of the target, the shutter is removed and thetarget material is sputtered onto the substrate using 200 W, directcurrent, with the substrate at 0V, grounded. The spacing between thesubstrate and the target is maintained at about 76 mm. Sputtering timesof 3 minutes and 30 minutes, and chamber pressures of 5 and 8 mTorr areemployed as shown in Table 1.

TABLE 1 Deposition Conditions Example Number EX. 2 EX. 3 EX. 4 EX. 5 EX.6 EX. 7 EX. 8 EX. 9 Sputter Target 1 1 1 1 1 1 1 1 Substrate-Si wafer100 yes yes yes yes Substrate-Corning 1737 glass yes yes yes yes ChamberPressure, mTorr 5 5 8 8 5 5 8 8 Deposition time, min 3 30 3 30 3 30 3 30

FIG. 6A is a secondary electron scanning electron micrograph at amagnification of about 50,000 that illustrates the surface of thedeposited layer of Example 7 using a deposition pressure of about 5mTorr and a deposition time of about 30 minutes. As seen in FIG. 6A, thegrains have an average grain size of about 125 nm.

FIG. 6B is a secondary electron scanning electron micrograph at amagnification of about 50,000 that illustrates the surface of thedeposited layer of Example 9 using a deposition pressure of about 8mTorr and a deposition time of about 30 minutes. As seen in FIG. 6B, thegrains have an average grain size of about 89 nm.

As illustrated in FIGS. 6A and 6B, most of (e.g., essentially all of)the deposited molybdenum, most of (e.g., essentially all of) thedeposited titanium, and most of (e.g., essentially all of) the depositedtantalum, are in one alloy phase that contains over 50 atomic %molybdenum.

The cross-section of the deposited film of Example 9 using secondaryelectron scanning electron microscopy at a magnification of 10,000 isshown in FIG. 7. FIG. 7 illustrates that the deposited material has acolumnar microstructure. The deposition rate of the Example 1 targetonto the substrates is about 62.4 nm/hr using the conditions of Examples2 through 9. The deposited films contains about 80 atomic % molybdenum,about 10 atomic % titanium and about 10 atomic % tantalum.

The thin films (having a thickness of about 200 nm) deposited bysputtering the Example 1 sputter target have an electrical resistivityof about 26.5 μΩ·cm and the thick films (having a thickness greater thanabout 1 μm) have an electrical resistivity of about 22.6 μΩ·cm.

When etched in ferricyanide solution at about 25° C., the depositedfilms have an average etch rate of about 61 nm/min. The adhesion of thedeposited film to the glass substrate varied from about 2 B to about 5B, and the adhesion of the deposited film to the silicon substrate isabout 5 B.

Example 10

Example 10 is prepared by depositing a 200 nm molybdenum containinglayer from the Example 1 sputter target onto a silicon substratefollowed by the depositing of a 500 nm copper (Cu) layer onto themolybdenum containing layer. The composition depth profile of themultilayered material is measured using Auger depth profile analysis.The sample is then annealed for 30 minutes at 350° C. and the Augerdepth profile analysis is repeated. FIGS. 8A and 8B illustrates theAuger depth profile for Cu, Si, Mo, Ti, and Ta, before and after theannealing, respectively. FIG. 9A illustrates the Auger depth profile forMo, Ti, Ta, and Cu, near the interface between the copper layer and themolybdenum containing layer, both before and after annealing. FIG. 9Billustrates the Auger depth profile for Mo, Ti, Ta and Si near theinterface between the silicon substrate and the molybdenum containinglayer, both before and after annealing. As seen in FIGS. 8A, 8B, 9A, and9B, the composition profile is about the same before and after theannealing step, and the molybdenum containing layer acts as a barrier toreduce and/or prevent the migration of Cu into the Si substrate and Siinto the Cu layer. X-ray analysis of the sample after annealing showsthat there is no detectable copper silicide. The annealing/Augerspectroscopy study illustrates the good barrier performance of the filmdeposited from the sputter target of Example 1. For example, the studyillustrates the ability of the Mo—Ti—Cr deposited film from the Example1 sputter target to prevent the formation of copper silicide afterannealing for 30 minutes at 350° C.

Examples 11-12 Molybdenum (50%) and Titanium (50%) Example 11

Comparative Example 11 is a sputter target including about 50 atomic %molybdenum and about 50 atomic % titanium. The sputter target isprepared using the method described for Example 1, except only thetitanium and molybdenum particles are used at an atomic ratio of 50:50of Mo:Ti, and the target is hot isostatically pressed at a temperatureof about 1325° C. and a pressure of about 100 to about 120 MPa for about4 hours.

Example 12

Example 12 is a 200 nm thick film deposited on a glass substrate usingthe method of Example 7, except the sputter target of Example 6 is used.The deposition rate is about 102.6 nm/min. The electrical resistivity ofthe 200 nm thick film is about 79.8 μΩ·cm. The adhesion of the depositedlayer to glass is about 5 B. The etch rate of the deposited layer isabout 77 nm/min. The deposited layer has a columnar morphology.

Examples 13-25 Molybdenum/Niobium/Tantalum

Example 13 illustrates a sputter target including molybdenum, niobium,and tantalum, and Examples 14-25 illustrate deposited films preparedfrom the sputter target.

Example 13 is a sputter target that is prepared by first blendingmolybdenum powder having a particle size of about 3-4 μm, tantalumpowder having a particle size of about 45-90 μm, and niobium powderhaving a particle size of about 10-45 μm to form a powder blend havingabout 80 atomic % molybdenum, about 10 atomic % niobium, and about 10atomic % tantalum. The blending is done in a V-blender for about 20minutes to obtain a homogeneous mixture of the three different powders.The resulting powder blend is then consolidated by uniaxially pressingwith an applied force of about 340,000 kg into pellets having a diameterof about 95 mm (i.e., a pressure of about 470 MPa) at a temperature ofabout 23° C. The pressed pellet is then encapsulated in a can made oflow carbon steel and hot isostatically pressed at a temperature of about1325° C. and a pressure of about 100 to about 120 MPa for about 4 hours.Thus prepared, Example 13 has a density which is greater than about 94%of the theoretical density. The consolidated material is then removedfrom the can and machined to a diameter of about 58.4 mm and a thicknessof about 6.4 mm.

Examples 14-25 are prepared by placing the sputter target of Example 13into a magnetron sputter deposition chamber using the conditionsdescribed in Tables 2A and 2B. The substrate is either a silicon wafer(100) orientation, or Corning 1737 glass. Prior to deposition, thesubstrate is cleaned by successive rinsing in ultrasonic baths ofacetone and ethyl alcohol. The substrates are then dried by blowingnitrogen gas. The substrates are next loaded into the deposition chamberalong with the sputter target. The target is sputter cleaned with anargon flow of at a pressure of about 5 mTorr at 200 W DC for about 10minutes. During the cleaning of the target, a shutter is placed in frontof the target to prevent deposition onto the substrate.

When using the glass substrate, the substrate is etched by sputtering at60 mTorr for 30 minutes to remove possible contamination on thesubstrate surface.

After the sputter cleaning of the target, the shutter is removed and thetarget material is sputtered onto a substrate using 300 W, directcurrent, with the substrate at 0V, grounded. The spacing between thesubstrate and the target is maintained at about 121 mm. Sputtering timesof about 5 minutes and about 30 minutes, and chamber pressures of about3, about 5 and about 8 mTorr are employed as shown in Tables 2A and 2B.

TABLE 2A Deposition conditions using the sputter target of Example 13target on silicon substrate. Example Number EX. 14 EX. 15 EX. 16 EX. 17EX. 18 EX. 19 Sputter Target EX. 13 EX. 13 EX. 13 EX. 13 EX. 13 EX. 13Substrate-Si wafer 100 yes yes yes yes yes yes Substrate-Corning 1737glass Chamber Pressure, mTorr 3 3 5 5 8 8 Deposition time, min 5 30 5 305 30 Thickness, μm 0.2 1.0 0.2 1.1 0.2 1.3 Etch rate, nm/min 447 484 502

TABLE 2B Deposition conditions using the sputter target of Example 7Atarget on glass substrate. Example Number EX. 20 EX. 21 EX. 22 EX. 23EX. 24 EX. 25 Sputter Target EX. 13 EX. 13 EX. 13 EX. 13 EX. 13 EX. 13Substrate-Si wafer 100 Substrate-Corning 1737 glass yes yes yes yes yesyes Chamber Pressure, mTorr 3 3 5 5 8 8 Deposition time, min 5 30 5 30 530 Resistivity, μΩ · cm 18.0 17.3 19.4 17.9 20.1 19.5

In Examples 14-25, the deposited layers are deposited at a depositionrate of about 33 to about 41 nm/min. Samples prepared with a depositiontime of about 5 minutes have a thickness of about 200 nm. Samplesprepared with a deposition time of about 30 minutes have a thickness ofabout 900 to about 1300 nm. The adhesion to the glass substrate of theExample 22 prepared at a pressure of about 5 mTorr is about 4 B. Theadhesion to the glass substrate of the Examples 20 and 24 prepared at apressure of 3 and 8 mTorr respectively is about 5 B. The adhesion to thesilicon substrate of Example 14, 16 and 18 prepared at pressure of 3, 5and 8 mTorr respectively is about 5 B.

The electrical resistivity of the deposited layers is given in Table 2Bfor Examples 20-25. The average electrical resistivity of the depositedlayer on the glass substrate is about 19.2 μΩ·cm for the layers having athickness from about 100 to about 200 nm and about 18.2 μΩ·cm for thesamples having a thickness greater than about 0.9 μm. The uniformity ofthe electrical resistivity is measured on Example 16, by measuring theelectrical resistivity at multiple locations on the 3″ wafer. Theuniformity of the electrical resistivity is the ratio of the standarddeviation of the electrical resistivity to the average electricalresistivity. The uniformity of the electrical resistivity of Example 4is about 0.07.

The etch rate of the deposited layers in ferricyanide solution forExamples 15, 17, and 19 are measured at 25° C. The etch rates aredetermined by dividing the change in thickness by the etching time. Theetch rates, in units of nm/min are given in Table 2A. The average etchrate for the films prepared with the Example 1 sputter target is about478 n m/m in.

Example 26 Molybdenum/Titanium/Chromium

The sputter target of Example 26 is prepared using the method of Example1 except the tantalum powder is replaced with chromium powder having aparticle size of about 10-45 μm. Deposited films are then prepared usingthe methods of Examples 2-9, except the sputter target includingmolybdenum, titanium, and chromium is employed. The deposited films havean etch rate (ferricyanide solution at about 25° C.) of about 13 nm/min.The deposited films have an adhesion to glass of about 4 B-5 B. Thedeposited films have an adhesion to silicon of about 5 B. The depositedfilms have a grain size of about 70-79 nm. The deposited films have anelectrical conductivity of about 31.0 μΩ·cm (for 200 nm thick films) andabout 27.1 μΩ·cm (for 1 μm thick films).

What is claimed is:
 1. A sputter target comprising: i) about 40 atomic %or more-molybdenum, based on the total number of atoms in the sputtertarget; ii) about 1 atomic % or more titanium; and iii) greater than 5atomic % of a third metal element, based on the total number of atoms inthe sputter target, wherein the third metal element is tantalum orchromium; wherein the total concentration of the molybdenum, titanium,and third metal element is about 95 atomic % or more, based on the totalnumber of atoms in the sputter target; so that the sputter target may beused for preparing a deposited film including an alloy, the alloycomprising molybdenum, titanium, and the third metal element.
 2. Thespatter target of claim 1, wherein the third metal element is tantalum.3. The sputter target of claim 1, wherein the third metal element ischromium.
 4. The sputter target of claim 3, wherein the totalconcentration of titanium and the third metal element is bout 45 atomic% or less based on the total number of atoms in the sputter target; andthe concentration of molybdenum is less than 85 atomic percent.
 5. Thesputter target of claim 1, wherein the concentration of molybdenum inthe sputter target is about 50 atomic % or more.
 6. The sputter targetof claim 5, wherein the sputter to at is substantially free of niobiumor contains less than 10 atomic % niobium.
 7. The sputter target ofclaim 5, wherein the concentration of titanium from about 5 atomic % toabout 25 atomic % based on the total number of atoms in the sputtertarget, and wherein the concentration of the third metal element is from5 atomic % to about 5 atomic % based on the total number of atoms in thesputter target.
 8. The sputter target of claim 1, wherein rein thesputter target includes: i) about 40% or more by volume of a first phasebased on the total volume of the sputter target, wherein the first phaseincludes molybdenum at a concentration of about 50 atomic % or more,based on the total number of atoms in the first phase; ii) about 1 toabort 40% by volume of a second phase based on the total volume of thesputter target, wherein the second phase includes titanium at aconcentration of about 50 atomic % or more, based on the total number ofatoms in the second phase; and iii) about 1 to about 40% by volume of athird phase based on the total volume of the sputter target, wherein thethird phase includes about 50 atomic % or more of the third metalelement, based on the total number of atoms in the third phase.
 9. Thesputter target of claim 8, wherein the concentration of molybdenum inthe sputter target is about 50 atomic % or more, the second phase ispresent at a concentration of 5 volume % or more, based on the totalvolume of the sputter target, and wherein the third phase is present ata concentration of 5 volume or more, based on the total volume of thesputter target.
 10. The sputter target of claim 8, wherein the thirdmetal element is chromium, the second phase is a discrete phase, and thethird phase is a discrete phase.
 11. The sputter target of claim 8,wherein the third metal element is tantalum, the second phase is adiscrete phase, the third phase is a discrete phase, and the first phaseis a continuous phase.
 12. The sputter target of claim 11, wherein thesputter target is capable of depositing by sputtering using a magnetrona deposition layer of about 200 nm in thickness on a clean siliconwafer, the deposition layer having an etch rate in ferricyanide solutionat 25° C. of about 65 nm/min or less.
 13. The sputter target of claim12, wherein the putter target is capable of depositing by sputteringusing a magnetron a deposition layer of about 200 nm in thickness on aclean silicon wafer, the deposition layer having an electricalresistivity that is less than the electrical resistivity of a depositionlayer having the same thickness prepared from a sputter targetconsisting of 50 atomic % molybdenum and 50 atomic % titanium.
 14. Thesputter target of claim 13, wherein the sputter target has a length ofabout 1 m or more and is formed by a process that includes a step ofrolling.
 15. A method or making a sputter target of claim 8, comprisingthe steps of: a. blending first particles containing at least 50 atomic% of molybdenum, second particles containing at least 50 atomic % oftitanium, and third particles containing at least 50 atomic % of thethird metal element; b. heating the blended particles to a predeterminedtemperature; c. applying a predetermined pressure to the blendedparticles for a predetermined time to form a heterogeneous material; andd. rolling the heterogeneous material to increase at least the length ofthe material; wherein the predetermined pressure is at least about 5000psi, the predetermined temperature is about 1100° C. or more, and thepredetermined time is about 1 hour or more.
 16. A process comp sing thestep of: depositing film on a substrate by sputtering the sputter targetof claim
 1. 17. An article including a substrate and a deposited layer,wherein the deposited layer is deposited from a sputter target of claim1, and the deposited layer includes an alloy including molybdenum,titanium, and the third metal element.
 18. The article of claim 17,wherein the deposited layer has an etch rate in ferricyanide solution at25° C. of about 65 nm/min or less.
 19. The article of claim 17, whereinthe deposited layer has are electrical resistivity of 40 μΩ·cm or less.20. A process comprising the step of etching the molybdenum containinglayer of the article of claim 17 at a rate of less than about 65 nm/min.21. A sputter target comprising: i. from about 40 atomic to less than 85atomic % molybdenum, based on the total number of atoms in the sputtertarget: ii. about 1 atomic % or more titanium, based on the total numberof stoma in the sputter target, and iii. 5 atomic % or more tantalum,based on the total number of atoms in the sputter target; so that thesputter target may be used for preparing a deposited film including analloy, the alloy comprising molybdenum, titanium, and tantalum.
 22. Asputter target comprising: i) about 40 atomic % or more-molybdenum,based on the total number of atoms in the sputter target; ii) about 1atomic % or more titanium; and iii) greater than 1 atomic % tantalum,based on the total number of atoms in the sputter target; so that thesputter target may be used for preparing a deposited film including analloy, the alloy comprising molybdenum, titanium, and the third metalelement; wherein the sputter target includes: a) about 40% or more byvolume of a first phase based on the total volume of the sputter target,wherein the first phase includes molybdenum at a concentration of about50 atomic % or more, based on the total number of atoms in the firstphase; b) about 1 to about 40% by volume of a second phase based on thetotal volume of the sputter target, wherein the second phase includestitanium at a concentration of about 50 atomic % or more, based on thetotal number of atoms in the second phase; and c) about 1 to about 40%by volume of a third phase based on the total volume of the sputtertarget, wherein the third phase includes about 50 atomic % or more ofthe third metal element, based on the total number of atoms in the thirdphase.